From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DF7EC4332F for ; Wed, 2 Nov 2022 10:53:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229537AbiKBKw7 (ORCPT ); Wed, 2 Nov 2022 06:52:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbiKBKw6 (ORCPT ); Wed, 2 Nov 2022 06:52:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 737371403C; Wed, 2 Nov 2022 03:52:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 12DD5617F0; Wed, 2 Nov 2022 10:52:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65E06C433C1; Wed, 2 Nov 2022 10:52:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667386376; bh=NDOSDtF1moYJudFzXEU8Fr9+WFsHcE/xRnSi1+ZcO7c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Na/BGUedFirgHaWPiyVX6ER5jxLKzRsnHS04v8ArlXi3JkKsB/MkA6Ku0a5LwoLb+ Dprv7i13JLcDhxy+iOP0LhPs//an9FpJoDmAgmfDxG6BetwzK+vivLBPCobjj19FEV aweGk86xTmX1kj2fJVg0+2dK4TavfmqBzmV417uvcpPAar7D/czSTLme1Wm4OGaSHQ qhzgURPCc3B4GQvVHW9Nte7PvR/QiIEu2vKD44OHHezyAIv+5LYWsMkPAIzyG9Lt8z dOm+0GbTP/xoDc5T+TDeetUejclFfv+icFJ4LkGzyWVwntGPeeYp+s3x3w2UNfpI5R 8HKwfwX8j/zFA== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1oqBMN-000123-Hg; Wed, 02 Nov 2022 11:52:40 +0100 Date: Wed, 2 Nov 2022 11:52:39 +0100 From: Johan Hovold To: Stephen Boyd Cc: Michael Turquette , Stephen Boyd , linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, patches@lists.linux.dev, Andy Gross , Bjorn Andersson , Konrad Dybcio , linux-arm-msm@vger.kernel.org, Dmitry Baryshkov , Johan Hovold , Ulf Hansson , Taniya Das , Satya Priya , Douglas Anderson , Matthias Kaehlcke Subject: Re: [PATCH] clk: qcom: gdsc: Remove direct runtime PM calls Message-ID: References: <20221101233421.997149-1-swboyd@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221101233421.997149-1-swboyd@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Tue, Nov 01, 2022 at 04:34:21PM -0700, Stephen Boyd wrote: > We shouldn't be calling runtime PM APIs from within the genpd > enable/disable path for a couple reasons. > > First, this causes an AA lockdep splat because genpd can call into genpd > code again while holding the genpd lock. > > WARNING: possible recursive locking detected > 5.19.0-rc2-lockdep+ #7 Not tainted > -------------------------------------------- > kworker/2:1/49 is trying to acquire lock: > ffffffeea0370788 (&genpd->mlock){+.+.}-{3:3}, at: genpd_lock_mtx+0x24/0x30 > > but task is already holding lock: > ffffffeea03710a8 (&genpd->mlock){+.+.}-{3:3}, at: genpd_lock_mtx+0x24/0x30 > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(&genpd->mlock); > lock(&genpd->mlock); > > *** DEADLOCK *** > > May be due to missing lock nesting notation I've seen this splat on sc8280xp as well but haven't had time to look into it yet. > Cc: Dmitry Baryshkov > Cc: Johan Hovold > Cc: Ulf Hansson > Cc: Taniya Das > Cc: Satya Priya > Cc: Douglas Anderson > Cc: Matthias Kaehlcke > Reported-by: Stephen Boyd We typically don't add Reported-by tags for bugs we find and fix ourselves. > Fixes: 1b771839de05 ("clk: qcom: gdsc: enable optional power domain support") > Signed-off-by: Stephen Boyd > --- > drivers/clk/qcom/gdsc.c | 64 ++++++----------------------------------- > 1 file changed, 8 insertions(+), 56 deletions(-) > > diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c > index 7cf5e130e92f..a775ce1b7d8a 100644 > --- a/drivers/clk/qcom/gdsc.c > +++ b/drivers/clk/qcom/gdsc.c > @@ -495,14 +451,11 @@ static int gdsc_init(struct gdsc *sc) > sc->pd.power_on = gdsc_enable; > > ret = pm_genpd_init(&sc->pd, NULL, !on); > - if (ret) > - goto err_put_rpm; > + if (!ret) > + goto err_disable_supply; The logic should not be inverted here (and only happens to work currently when you have no regulator or the gdsc was off). > return 0; > > -err_put_rpm: > - if (on) > - gdsc_pm_runtime_put(sc); > err_disable_supply: > if (on && sc->rsupply) > regulator_disable(sc->rsupply); Johan